Geologic Unit: Ortley

Usage:

Ortley member (informal) of Grande Ronde Basalt of Columbia River Basalt Group (OR*,WA*)
Ortley member (informal) of Grande Ronde Basalt of /Yakima basalt subgroup [informal] of Columbia River Basalt Group (OR*,WA*)

Informal. The rank or lithologic term should not be capitalized. [Yakima basalt subgroup considered informal and should not be capitalized. "Subgroup" not recognized as a formal stratigraphic rank term (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). Columbia River Basalt Group adopted by the ID, OR, and WA Geol. Surveys, and the USGS (rules suspended).]

Geologic age:

late Tertiary (middle Miocene)*

Type section, locality, area and/or origin of name:

Named from excellent exposures on WA side of Columbia River near Columbia Hills water gap commonly known as the Ortley anticline (see Reidel and others, 1989).
Reference localities: (1) Columbia Hills water gap (Ortley anticline), [north of] WA State Route 14, in secs. 5 and 6, T. 2 N., R. 13 E., The Dalles North 7.5-min quadrangle, [Klickitat Co., southernmost WA]; and (2) Bingen, WA, along WA State Route 14, in secs. 32, 33, and 34, T. 3 N., R. 11 E., White Salmon 15-min quadrangle, [Klickitat Co., southernmost WA] (Reidel and others, 1989).

AAPG geologic province:

Eastern Columbia basin*